1. Field of the Invention
The present invention relates to an electromagnetic driver with lead-out structure for coil, especially to an electromagnetic driver such as voice coil motor or actuator with lead-out structure for coil.
2. Description of Prior Art
Electromagnetic drivers such as voice coil motors (VCM) and electromagnetic actuators are widely used in controlling lens movement for autofocus camera. FIG. 1 shows a schematic diagram of a prior art lens focusing mechanism with image stabilization, and FIG. 2 shows a sectional view along line A-A in FIG. 1. The lens focusing mechanism shown in FIG. 1 employs voice coil motor 100 for focus control along Z axis (zooming in and zooming out direction) and actuator for image compensation in X-Y planes to provide stabilization. More particularly, the voice coil motor and the actuator are operated by applying current through coil to generate electromagnetic field and the electromagnetic field has interaction (repulsive or attractive action) with magnet. To connect the connecting wire of coil to the relevant electric conductive member (such as spring), the connecting wire of coil is soldered to the conductive member and hen the conductive member is electrically connected to the driver. Therefore, electric current can be conducted to the coil for further magnetization.
However, the soldering task for the coil wire become more difficult as the electromagnetic drivers used for mobile phones and cameras are more compact. Moreover, the electromagnetic drivers are also difficult to automatically manufacture because manual labor is required for soldering. Taking the manufacture of voice coil motor as example, the voice coil motor 100 shown in FIG. 2 has a lens holder 101, lens 102 arranged inside the lens holder 101, a coil 103 around the lens holder 101, upper and lower springs (resilient plates) 104 and 105 arranged atop and below the lens holder 101. During the manufacture of voice coil motor, the lower spring 105 is first assembled to a base 106, and then the lens holder 101 is connected to the lower spring 105. Afterward, the coil 103 is wound around the lens holder 101 and the lead-out wire of the coil is soldered to the lower spring 105, whereby the process for assembling other components can be followed. The soldering of the lead-out wire of the coil to the lower spring 105 needs to be performed manually, thus the process is inconvenient.